The present invention relates to the field of mass spectrometry and ion mobility spectrometry.
It is well known that if analytes carried in vapour, droplets or gases are allowed to interact with an electrospray ionisation (ESI) cloud at atmospheric pressure, they become ionised. The approach of mixing a stream of gas containing species to be analysed with a flow of solvent droplets emitted from an ESI source results in the production of analyte ions, which are then transferred to the sampling orifice of a mass spectrometer or ion mobility separator. This technique is known as secondary electrospray ionisation and is performed at ambient pressures prior to the analyte entering the instrument through the sampling orifice.
The sensitivity of such secondary electrospray ionisation devices is dependent on the critical alignment of the electrospray charged droplet stream and the impinging beam of analyte, be it a gas flow carrying the analyte or a plume of ejected material such as in a LAESI technique. Further, it is then critical that the resulting charged droplet stream containing the analyte is aligned with the sampling orifice of the analyser.
It is desired to provide an improved method of mass spectrometry or ion mobility spectrometry, and an improved spectrometer for performing such a method.